SICAMG

Took a spin at Pocono for a roll race event and didn't do to well. Car ran 9.5 second times but was off by 10-12 mph. Car pulled real hard and seemed to pull hard all threw the power band but the mph said different. Temps where at 120 max on every run with a 77 pulley and it was 80* outside. Great time though !!
Some extremely fast cars where there running close to 200mph !!!!....mostly the GTR's and Vette's !! Those GTR's are incredible !! I will post a couple more videos soon.



Same video ...one out side the car one inside. I never new that supercharger was so loud !!! Love it !!!


One more vid ..it's a couple years old...to give you guys an idea of what its all about. Would love to put a group together for next year. You have a giant garage to be in ,food stand,fuel and what ever !!

GatorMB

Looks like fun,Are you tuned W Rev Limitations removed?

These cars should get close to 180. There are a couple of you tubes of the CLK 55 breaking 170 mph.

Thanks for sharing

Enjoy, Gator

SICAMG

This is only a 1/2 mile event so 180 is out of the question. No tune on car. Shifted at 6200 rpm and a 10.8 AFR.

GatorMB

Check:
10.8 is lean and close to vanishing point. A tune from Eurocharged will get you in game if desired.
Still impresive to run at Pocono.
I autocross with the PCA and we get Sebring and Daytona occasionally.
I'm not that hard core yet LOL

Best, Gator

Manuyc

nice

GatorMB

Manuyc:

Has the Grocery List to smoke a Hellcat.
What is your Top End and 1/4 ET?

Cheers and Happy 4th folks!!!

Hulk

10.8 is not lean at all

GatorMB

Agreed its in the green but A/F with performance tuning will yield different results.

So many combinations out there. He did good for 1/2 mile run in street trim.

All the Best

drothgeb

You are confused about AFR or maybe just misspoke? You said 10.8 is too LEAN, almost to the point of vanishing?

10.8 is solid but if anything you can LEAN it out slightly more for a little more power. I probably wouldn't **** with it but if you wanted to squeek out a touch more power you cold probably LEAN it out to 11.0-11.5 range and still be safe.

I'm guessing you maybe just meant to say rich in your first post.

austingtir

10.8 is rich...... Someone beat me to it. I dont think theres a massive difference in power between 10.8 and 11.5 just will feel crisper a few hp I have onboard wideband and run around 11.8

SICAMG

Car only ran to 141 mph but et was 9.5-9.6 . Should have been in the 152 mph or better zone. After pondering this it's clear that although the car pulled like a freight train I did not have the HP to carry me through the top end. Maybe with a kleeman tune the timing pull was to much for power with my IAT's at 120...
which I thought was pretty good considering the temps outside and how long I was in line to go.
I will load some videos filmed from outside the car to get a better idea.

10.8 IS rich and i do run 100 octane but i need to stay safe and dont trust tunes. I have to drive the car 4 hours to get there,beat it silly and then drive home 4 hours......10.8 is just fine !! LOL

I do need to fix this though or not going back unless there's more to gain. That personal ego thing ya know LOL !!! Keeps you up at night thinking!

Hulk

Were you running 100 octane on 93 tune that will make you run rich for sure
As for the mph, was your timing getting pulled ?

GatorMB

I have a new AEM A/f Install but right bank has a faker bung that tells the system to run rich. I am in the 14.x ranges most of the time until this is corrected.

Also use a vachume boost gauge and vachume works with engine economy until one installs radical camshaft.

The 10.8 tells me the injectors are maxed boost is controlled and the car is giving its best. My 14 is in the red at idle. Green is normal for un modified cars. Modified cars should report A/F in the red.
Meth will enhance the reading but cooling the combustion temps will effect the A/F readings as well. in the form of Red readings because of the lower exhaust temps recorded by A/F O2. These will record in spec on a tuned built engine.

Comments and more data welcome here.
No offense intended when reading my own results

drothgeb

The octane of your gas will not change your afr
That is unless you start to get above 108 where the specific gravity of the fuels start to drop significantly and in that case it will begin to lean you out slightly. Octane is a measure of the fuels resistance to detonate solely due to heat and compression. It will help you prevent knock in your motor from running too hot, and allow you to tune more aggressively but it will not in itself change your afr.

Running 100 octane on a 93 octane tune wont benefit you(as long as you aren't experiencing any knock and resulting timing retard), but it wont hurt you either.

I am also... super jealous of you SICAMG I have a ran down 1/4 mile track a little ways from where I live that I am excited to get the new car out to. But I would be a kid before Christmas with a track like that to play on!

drothgeb

AFR at idle and under WOT will be very different. At idle you are shooting for stoich, or a perfect burn which is 14.8 for the best MPG. At wide open throttle that would be much too hot of a burn, so you go richer usually to 11 to 12 range. The extra fuel from being slightly richer than stoich vaporizes and absorbs heat which is what cools down the chambers. Running lean at WOT is dangerous, I would normally not want to see an AFR >12 at WOT.

The AFR does not tell you anything about your injectors. That is going to be based on your tune and you would need to monitor injector duty cycle to see what they are running. If you have 100% duty cycle to keep your WOT AFR below 12 then you are out of fuel, but if you are running too lean... like 12.5 with 75% injector duty cycle, its your tune.

Meth will do a few things. It will make your AFR slightly ritcher(lower number) because you are putting a fuel into the air intake, and it will cool the combustion cycle in the same way I talked about above. It will vaporize and through the phase change from liquid to vapor it will absorb heat removing it from its surroundings. If you didn't want to affect your AFR with a meth injection kit you can spray straight water to get the same cooling affect but without needing a meth specific tune.

SICAMG

Hulk I ran the 100 just to be safe with the heat. The tune is kleeman from what i have found when i bought the car. Since I was running the fan on over ride and shutting the car off multiple times in the staging lanes for some reason it screwed with the recording of the runs and would get "stuck" at its starting parameter? so when I figured out what I was doing wrong finally, I ran out of ice for the inter cooler and that was it for the day.

Also the elevation was 1,800 feet so boost was down about a pound...15 to 14

Hulk

On stock tune 100 octane will make u run rich and will prevent detonation
I have seen it on my car

drothgeb

Maybe you saw your car running rich with 100 octane and didn't account for another factor that will actually affect AFR like altitude or temperature or spraying meth or who knows what.

But higher octane does not prevent detonation by making your mixture more rich. It generally does not change AFR.

Hulk

No meth
Just the higher octane

GatorMB

Wealth of information,

It seems I have a bit more research to overcome and I appreciate the positive input.
Sorry to impose the added criteria in the OP thread but maybe a few will reap some benefit from the understanding Wideband gauge.

Cheers, Gator

Blade Canyon

Nice video! Looks like fun, thanks for posting.

SICAMG

Well found something interesting today. Never did any pulls watching my timing and today I did.
I'm trying to see why the car is not pulling hard up top.
Timing will slowly get pulled all the way to 5 degree's and sometimes will bounce to 0*. It will show 24-22-20 all the way down as the revs come up. Temps never go above 120* and that's at the end of the 1/2 mile with AFR at 10.6 or so.
The tune is a very old Kleeman but they have no record so can't get info.
This timing "pull" explains a lot if it's correct. What is a "normal" timing?

I'm used to my old Ford Mustang 302 Renegade engine with at least 24* on the top end LOL. I know these engines are more sensitive.

drothgeb

Some one just posted a 180mph run they had here:
https://mbworld.org/forums/w211-amg/...h-iat-log.html

I glanced at his log and 20° seemed about what he had at most points.

SICAMG

Man I am all out of whack!! His numbers jump around a lot but level off and stay steady.
It looks like I have some work to do !!!!

FunkTron

wait....you have a 77mm pulley and no tune?